1. Field of the Invention
This invention relates to an inexpensive, fully practical, and highly improved mast or tower having a swingable antenna-carrying column and particularly, to one that after installation, will withstand high winds without buckling failure. A phase of the invention deals with a structure that is balanced in such a manner as to assure a full desired height with exceptional ability to withstand winds, and to enable a one-person "down" and "up" swinging of it for maintenance, change of antenna, etc.
2. Description of the Prior Art
Although so-called radio or antenna towers have been in use for a number of years, it has been my experience that those which are suited for maximum reception, for example, up to the sixty foot height limitation, have been too expensive from the standpoint of their construction and installation, and are difficult to service. During the bad weather of this year, I found that the prior art types tend to fail with winter wind gusts in the neighborhood of 65 to 75 miles/hour, leaving a mass of members and antenna wires. There has been a need for a relatively inexpensive, easily installed and maintained tower which will essentially withstand such wind gusts and which will enable a radio operator to, himself or herself, without the aid of others, service it from the standpoint of its antenna and rotor.
Types with which I am familiar employ a tower whose column is pivoted at a position that is located considerably below and at least not above a center portion of the length of its column, such that its actual center of gravity or tilt is located well above such a position. The center of tilt is also further upwardly advanced when an antenna and/or rotor are mounted on the upper end of the column. The length of the fixed support in such a construction may be only slightly more than the height of a person. For example, the total length above the ground may be about ten feet, as compared to a total upright length of column or mast of about sixty feet. It appears that the purpose in doing this has been to minimize the required length or height of supporting structure and to keep the swing point within the approximate reaching height of the arms of repairmen.
The great off-balancing of weight of the remaining fifty feet of the column plus the weight of the antenna and motor makes a down-swing of the column a somewhat dangerous operation, and although it is controlled by a cable and winch, the amount of control and manual force required for swinging the antenna to and retaining it in a lower maintenance "down" position and for moving it to and retaining it in an "up" position and while the winch is being latched, has been found to be such that at least two operators are required. The winch ratchet has to be retained in a locked position and presents a hazard, in that it is not foolproof and is subject to slippage or release, which may result in a violent downswing of the mast or column.
Other forms of towers have columns using demountable, interfitting members requiring complex, tent-like assemblies or guy wires. They have been found to be very expensive in their construction and of limited practicability from the standpoint of maintenance and repair, and from the standpoint of lack of resistance to damage under bad weather conditions. In other words, they will not withstand the vicissitudes of the ambient environment.